Not a surprise. The title had a very bad press on PC and I really don't know why IW spent the money the did for the whole matching making element as it was always looking to be a waste of effort.
Much as I still game on PC, there are titles I simply don't bother with now, this being one of them. No SDK, dedicated servers, etc. makes this simply redundant for me. I suspect it probably sold okay through Steam, but nothing like the console sales.
I found MW2 to be disappointing for my tastes anyway, having bought it on PS3 for my son. He played through the SP and thought it was weak after MW, however he does enjoy the MP, but even there he's now split between playing the original or MW2.
I really felt MW2 was a money exercise and nothing more. The SP is weak and not worth it and while the online is great, you're basically paying a fortune for a revamp of something you already have if you have CoD4.
Activision must love it though. Can't wait to see MW3's even shorter SP campaign with even nuttier story and how they re-sell more or less the same MP all over again.
I does annoy me to know Bobby's laughing at the masses though as he snorts cocaine off some whore's breasts, amazed how many people, particularly in the US/UK, will pay through the nose to have the same thing sold to them again and again with minimal refinements.
My, I'm feeling cynical this morning!
Try to be reasonable... its easier than you think...
